Add MSC or ASC as a parent when a MSC or ASC code is added

[teolemon]

What

• Add MSC or ASC as a parent when a MSC or ASC code is added
• Probably to be integrated at the level of the Packager Code

  robotoff/robotoff/insights/importer.py

  Line 474 in 5b9252d

  if cls.is_prediction_valid(product, prediction.value) # type: ignore

• Add the en:sustainable-seafood-msc in labels

Part of

[alexgarel]

@teolemon I'm a bit lost because the ticket description is a bit cryptic.

The scope is just to add the asc or msc label on the product right ?

(what is this notion of "parent" in the ticket ?)